Wales may be saying farewell to their long-serving wing Shane Williams on Saturday but their focus is on the future. It is some while since the World Cup semi-finalists enjoyed sustained success and after a campaign in New Zealand that fired the public imagination in one of the few nations in the world where rugby union can claim to be the national sport, the Welsh Rugby Union is wasting no time in ensuring there is a legacy for the game to build on.

The governing body appointed an extra 18 development officers throughout the country last month to exploit the explosion in interest generated by Wales's World Cup exploits: there was a bigger crowd in the Millennium Stadium to watch the semi-final against France on a big screen than there was at the ground staging the game, Auckland's Eden Park, and a fervour rarely seen since Welsh rugby's golden era in the 1970s.

The WRU, which too often in the past has preferred to bask in the glory of success rather than attempt to harness it, has initiated a project called Heart of the Nation – Join the Beat, which is designed to bottle the spirit of the World Cup and ferment something even stronger that will sustain the game well beyond the next two World Cups.

Rugby developed in Wales from the 1870s and it quickly established cultural roots, coinciding with a great industrial explosion that helped a new awareness of Welsh nationhood. It was through rugby, the 1905 meeting between Wales and New Zealand in Cardiff, that Hen Wlad Fy Nhadau became the Welsh national anthem and it is that age-old political and social connection that the WRU is looking to tap in to.

"The players did us so proud in the World Cup and it was a fantastic experience," says Roger Lewis, the chief executive of the WRU. "We have to look forward now, getting out there and doing something. It is critically important that we develop the game at grassroots level and that is what Join the Beat is all about. Clubs all over the country will open their doors to the public one day in January to show people what rugby offers for everyone.

"These are very challenging times economically and it looks like staying that way for the next few years. Last year we put £1m in real cash into buying equipment for clubs throughout Wales and this year we are offering financial support to communities and clubs. Rugby clubs help bind communities together and as a game we can help build people's self-confidence and self-respect. Rugby is the national sport of Wales and it is based on community."

The south of Wales is a village when it comes to rugby. The Wales flanker Dan Lydiate was asked this week whether he had become more recognisable in public after the World Cup. He replied by recounting an anecdote about Luke Charteris, not long after he had returned from New Zealand.

The second row, who at 6ft 10in is probably not the hardest player in the squad to pick out, filled up his car at a petrol station in Newport and as he went in to pay, he found everyone staring at him. By the time he reached the till, he received a round of applause.

Since the 1970s the rare moments of success Wales have enjoyed – 2005 and 2008 are recent examples – have been transitory, not least because they were not built on anything, happy accidents almost. The Wales head coach, Warren Gatland, who is starting his second four-year period in charge, appreciates that, while he and his players may bask in the afterglow of Wales's best World Cup campaign for 24 years, the mood in the country can quickly change: it is only a year ago that the WRU was being criticised for awarding Gatland a new contract.

"The Welsh public can turn on you pretty quickly if you do not perform," he says. "We have blooded a number of young players this year who have come through the academy system. They have a great work ethic and the time when rugby had a drinking culture is unknown to them. Their attitude has rubbed off on the older players and one aspect about our World Cup campaign is that the youngsters feel disappointed, not satisfied. There is a sense of emptiness because we came so close to making the final and, despite the reaction here to what we did in New Zealand, we will make sure they do not get ahead of themselves."

The young players set their elders the example during the World Cup and the way Wales managed the squad is being looked at by England after their campaign ended in acrimony and recrimination. It was not that the Welsh players were a bunch of ascetics who touched nothing stronger than a glass of orange juice, but they were encouraged to relax within the confines of the team hotel.

It was not a tour without incident and one player, who said more than he should have done after the quarter-final victory against Ireland, was told the following morning that if he did not make an immediate, personal apology to the person (who was not part of the Wales party) he had offended, he would be on the next plane home. Wales were able to keep the incident unreported because it happened out of the public gaze.

Attitude is a key determinant in the promotion of players from the academy. One player, who earlier this year filled in a questionnaire after an age-group training camp and complained that he had expected to be supplied with more, was told that what mattered was not what was given to him but what he himself gave.

"What happened in New Zealand will make us work harder, not less," says Joe Lydon, the WRU's head of rugby, who is in charge of development. "We are a small country and we have to maximise our resources. We have to do more in the north of the country, for example. George North came from there and he proved himself in the World Cup at the age of 19. We have to join it up: we have a number of players coming through the system, and the regions deserve great credit for the work they are doing, but there can never be too many."

The fixture against Australia is more than a send-off for Williams after an international career spanning 12 years and more than a chance for Welsh supporters to salute the World Cup players. Wales have beaten Tri-Nations opposition only three times in 45 matches in the professional era; for all they achieved in the World Cup, in New Zealand they lost to South Africa and the Wallabies. For Gatland it is about taking the next step – not looking back.

"It is important we build on the performances in New Zealand," says Rhys Priestland, the fly-half who made a considerable impact in the World Cup. "At the end of the day, we did lose to South Africa, France and Australia; as a squad we are pretty disappointed with that. We need to get a victory against one of the southern hemisphere teams to prove to ourselves that we are good enough. We have that chance on Saturday."